Preloader not displaying progress on externally loaded jpg


I am in the process of making an interactive tour plan, which quite simply is a floor plan of a building which when interacted with by the user shows a description and image of the room in question. With the image I am loading the jpeg externally (using a tutorial I found on the web) and it works fine except the preloader, which is a component does not work, it sticks on 0% and then the image pings in. I’m not really sure why this is happening - can anyone help?

The fla file can be found here:

Many thanks